title: Inhibition of long-distance movement of RNA silencing signals in Nicotiana benthamiana by Apple chlorotic leaf spot virus 50 kDa movement protein.
abstract: Apple chlorotic leaf spot virus 50 kDa movement protein (P50) acts as a suppressor of systemic silencing in Nicotiana benthamiana. Here, we investigate the mode of action of P50 suppressor. An agroinfiltration assay in GFP-expressing N. benthamiana line16c (GFP-plant) showed that P50 could not prevent the short-distance spread of silencing. In grafting experiments, the systemic silencing was inhibited in GFP-plants (scion) grafted on P50-expressing N. benthamiana (P50-plant; rootstock) when GFP silencing was induced in rootstock. In double-grafted plants, GFP-plant (scion)/P50-plant (interstock)/GFP-plant (rootstock), the systemic silencing in scion was inhibited when GFP silencing was induced in rootstock. Analysis of P50 deletion mutants indicated that the N-terminal region (amino acids 1-284) is important for its suppressor activity. In gel mobility shift assay, P50 lacks binding ability with siRNAs. These results indicated that P50 has a unique suppressor activity that specifically inhibits the long-distance movement of silencing signals.
authors.affiliation: The United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Yaegashi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tamura
authors.forename: Masamichi
authors.initials: M
authors.lastname: Isogai
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yoshikawa
mesh_terms: D001483:Base Sequence; D052677:Flexiviridae / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics; D008970:Molecular Weight; D010935:Plant Diseases / Q000235:genetics / Q000821:virology; D053830:Plant Viral Movement Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified; D011485:Protein Binding; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics; D017384:Sequence Deletion; D015398:Signal Transduction; D014026:Nicotiana / Q000235:genetics* / Q000821:virology*
chemical_list: D053830:Plant Viral Movement Proteins; D018749:RNA, Plant; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins